A woods riding guy I occasionally ride with rides an 89 cr 500 with a 28 oz flywheel weight added. I rode it for about 10 mins and was very impressed with its manners. It delivered power very similar to my 426. Not scary at all. His buddy had the same bike w/o the flywheel weight. I rode it about a nanosecond and handed it back. (I was scared)!!! This guy loved the power delivery and a minute later was telling me about all the broken bones he sported from that bike. Go figure!